import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/index")
public class IndexServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=utf8");

        HttpSession session=req.getSession(false);
        if(session==null){
            resp.getWriter().write("<h3>当前尚未登录！<h3>");
            return;
        }

        Integer visitCount=(Integer) session.getAttribute("visitCount");
        visitCount+=1;
        session.setAttribute("visitCount",visitCount);
        resp.getWriter().write("<h3>visitCount: "+visitCount+"<h3>");
    }
}
